Verification
of ORP electrodes
First
look for broken sensor (platinum ring or tip). If the
sensor seems to be OK, make sure your ORP sensor is
well conditioned (soak sensor into HI 7091L or HI 7092L
solution for 15 minutes). Also make sure the electrode
is fully filled with proper electrolyte. If the sensor
is still giving bad readings, see cleaning procedure
and preparation & testing of ORP electrodes.
Cleaning & storage of ORP electrodes
ORP
electrodes are cleaned with the same cleaning
procedure used for pH electrodes. On ORP electrodes,
this cleaning procedure will clean the electrodes
junction.
In
addition to that, platinum or gold tips & rings
can be clean as follow:
Platinum
tip or ring: Soak the electrode into HI
7092L solution for 30 minutes.
Gold
tip or ring: Soak the electrode into HI
7091L solution for 30 minutes.
It
is recommended to make a quick test with HI 7021L
or HI 7022L prior to use.
When
not used, ORP electrodes should be stored into HI
70300L storage solution.
Preparation & testing of ORP electrodes
ORP
electrodes need to be conditioned prior to use.
When
the electrode is new, soak the tip in warm tap water.
This will enhance the flow of the reference junction.
To check function of the electrode, immerse the tip
in ORP solution HI 7021L or HI 7022L. The reading
should be +/- 50mV from the value indicated on the
bottle.
If
the reading is not within +/-50mV, oxidizing or reduction
treatment with HI 7092L or HI 7091L is required. It
will also prepare the electrodes surface and
speed initial response time. Since in-line process
electrodes are already in a solution, a simple test
with either HI 7021L or HI 7022L will show you the
electrodes condition.
Should
your probe not be accurate enough after conditioning
& testing, follow the cleaning
procedure.
Gold tip vs Platinum tip
ORP
sensor, platinum or gold ?
Platinum
sensor:
use in oxidizing reaction (above 500mV) such as pools
& spas, municipal drinking water.
Gold
sensor:
use in reducing environment (below 500mV) such as
galvanic applications, mining industry (Cyanide).
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